Ballast-cleaning machine



H. D. PRATT.

BALLAST CLEANING MACHINE.

APPLICATION FILED NOV- 3, I919.

Patented Jan. 31, 1922.

H. D. PRATT.

BALLAST CLEANING MACHINE.

APPLICATION FILED NOV. 3,1'9I9.

Patented Jan. 31, 1922.

4 SHEETS-SHEET 2- I Jim/e72 M7. 61 .DPaiZ H. n. PRATT.

BALLAST CLEANING MACHINE.

APPLICATION FILED NOV- 3. 1919.

1,40%,999, Patented Jan. 31, 1922.

' 4 SHEETS-SHEET a.

lzfz'iness 1727672307" flow-6Z1 D Frai Zforngys H. D. PRATT.

BALLAST CLEANING MACHINE.

APPLICATION FILED NOV- 3. 1919.

Z 2 m4 9m fl/ mm TJH as 6 t m 8 h D/ 9v 3111M imam J 12 men in 1 well D,Prafi I flitor'ne s HOWELL D. PRATT, OF PHILADELPHIA, PENNSYLVANIA,ASSIGNOR '10 LIN K-BELT COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

BALLAST-CLEANING MACHINE.

To allwhom it concern and 'State of Pennsylvania, have invented acertain new and useful Improvement in Ballast-Cleaning Machines, ofwhich the following is a specification.

My invention relates to improvements in machines for mechanicallycleaning and screening railroad ballast. One object of my invention isto provide a new and improved form of machinery which will beself-propelled and which will move forward automatically at a ratebearing a proper relation to the speed of excavation and screening sothat a small crew may be used and' that crew may limit its activities tokeeping the machine in operation'and'feedmg ballast 'to it from betweenindividual ties so that when the machine has-cleaned the ballast frombetween the line of track or alongside a line of track, it will alsohave cleaned a certain amount of ballast from between the individualties of each track thus adding to the effectiveness of the cleaner.Another object is to provide a power driven ballast cleaning machine theunits of which are small and light enough so that no extra crew isneeded beyond that ordinarily operating the machine, for handling it andmoving it into and out of operating position. Another object, of course,isto provide such a machine as will be safely positioned in theclearance space between two railroad tracksor alongside a railroad trackand so that it will not be necessary to move it away-from its workingposition when a train goes by. Another object is to. provide means forautomatically guiding the machine as it moves forward 'so as to keep itin the clearance space and prevent it from moving laterally toward thecenter line of either track orto-. ward the center line of any trackalong which it works, which movement might, if

not prevented, bring the machine out of the clearance space into thedanger zone.

In order toaccomplish these objects, I provide a flat low frame restingpartially upon the ground or the surface of the ballast, or the surfaceof the ties in the ballast, and associate with it a toothed driving beltor belts, which belts carry part or all of the load and. are inengagement for a portion of Specification of Letters Patent. Applicationfiled November 3, 1919. Serial their length, with the supporting surfaceso when they are moved and travel around sprockets on the frame, beingdriven by the power source, the apparatus will move for-- ward. providea single power, source which drives these belts and operates anexcavator extending down below the surface of the material and adaptedto carry material up above the surface and discharge it on the screen.The screen and excavator are both driven in unison from the singlemotive device. After the ballast is cleaned by the screen, it passesover beneath the frame back into the space beneath the track and thefines which have been taken out by the screen drop into a box beneaththe screen whence they may be removed.

As the machine is moved forward, it is gulded to prevent lateralmovement and preserve parallelism with the tracks, by guiding memberswhich engage one or more of the rails of the track and which may engageeither the web of the rail or the upper surface.

I have shown a preferred form of guidmg means wherein rollers engage theoutside walls of the webs of the two inner rails of each track, andmeans are provided whereby when this roller comes to a fish plate orangle bar, it tips back throwing another roller in front into.engagement with the rail thus jumping the fish plate. This makes sure ofPatented Jan. '31, 1922.

ties on the surface of the web against which 1 the guiding membertravels.

In order that the different parts of the device may be light enough forthe working crew to pick them up when through work, the gasoline engine.which generates the power together with the generator and reel of cableare mounted on a single fixed frame which is itself of such size that itis entirely within the clearance space and the screen device travelsforward doing its work and drawing out the cable. When thecable is alldrawn out, the crew carries the generator set forward winding up thecable and the cleaner again moves forward taking another bite. .Inactual practice, it ispossible to operatethe device by having. theballast cleaning part naive. constantly forward and by havingthe-p'owergenerating part of the apptaratuslmove. forward by serles of separate sens.

My invention is illustrated more or less diagrammatically in theaccompanying drawings wherein- Figure 1 is a side elevation;

Figure 2 is a plan view;

Figure 3 is an end view with parts in section;

Figure 4 is a diagrammatic showing of the entire apparatus;

Figure 5 is a plan view of the preferred form of the guiding apparatus;

Figure 6 is a section through the propelling apparatus;

Figure 7 is a detail taken from Figure 6;

Fig. 8 is a cross section through the lower run of one of the belttreads.

Like parts are indicated by like characters throughout.

The main supporting frame is made up of two side members A A, turnedupwardly at their forward ends as at A A and having broad under bearingsurfaces as indicated. These members are tied together by cross braces AA and plates A A which latter extend inwardly from the cross members A Atoward the center of the apparatus and terminate where they engage theinner side frame members A A which extend forwardly and upwardly tosupport at their forward upward ends, the brackets A A. These bracketshave pivoted thereon, the side members A A" of the excavating ladder andcarry the quadrants A".

notched as indicated, to be engaged by a pin A in the side frames of theexcavating ladder whereby the excavating ladder itself may be locked inany angular position; A A are slidably mounted guide arms projectingoutwardly from the frame members A A, they carry rail web engagingrollers A and are yieldinglythrust outward by spring A. Their inwardmovement is so limited that while they have suflicient excursion topermit the rollers to pass by the angle bars, the apparatus is alwayscontained within the clearance space. A is a baffle plate which issupported on the rear end of the quadrants A and prevents the overthrowof dirt and stones.

B is a head sprocket. B is a tail sprocket. Mounted on the excavatingladder B is an excavating chain passing over the head and tail sprocketsand carrying buckets B which buckets pick up dirty ballast B anddischarge it onto a reciprocating screen B The fines which pass throughthe screen are caught in a dust box B extending down below the frameinto the hole made by the removal of the ballast, and the clean ballastpasses back over the screen to fill up the .hole after the dust box haspassed. B is a driving sprocket associated with the head sprocket B andit is driven by means of a sprocket chain B from a jack shaft B whichjack shaft is mounted for rotation on the frame A. This jack shaft isdriven by the eccentric shaft B mounted 'for rotation also on the frameA. B B are eccentrics on the shaft 13 engaging eccentric straps B whichin turn are mounted on the eccentric rods B pivoted to and driving thescreen B B is a motor. It drives the eccentric driving shaft B by meansof a a silent chain 13 to furnish the powerto operate the excavator andreciprocate the screen.

The forward end of the apparatus is supported on the runner-like undersurfaces means of a gear B and a pinion B from of the side frames A A.The rear end is supported on a kind of caterpillar track arrangementmade up of the endless toothed link belt treads C, oneunder each of thethese wheels and when both are in opera-- tion, the two shafts aredriven by the reciprocation of the driving lever, but if it is desiredto drive only one of the traction members this may be accomplished bydisengag- 1 ing one of the ratchets or the entire drive may bediscontinued by disengaging both the ratchets. Extending rearwardly fromthe two eccentric straps B is a yoke C and this yoke has a rearwardlyextending projection C pivoted to the driving lever, the angle ofmovement of which may be varied by varying the pivot point of theeccentric strap on the driving lever.

The screen B is reciprocated by the rota tion of the shaft 13 and themovement of the eccentric members B, which are linked to the screen bythe yoke or parallel. members B B shown in Figure 2.

In Figure 5 is shown the modified preferred form of guiding mechanism. Dis the railroad rail cut away to show the web at D D is a guide armpivoted on the frame member A and having rollers D adapted yieldingly tobe pressed against. the web D by the heavy spring D. It must beunderstood that there is a similar assembly on the other side of theapparatus and that the size and relation of the parts are such that thepivoted arms .are substantially perpendicular to the axis of movement.The arm D is prevented from swinging clear around by the stop vD Thesesprings are stifl and heavy and as theapparatus moves forward, theserollers are firmly held against the rail webs and prevent lateralmovement of the apparatus. When the rollers strike an angle a gasolineengine E and late, however, as at D", they cannot pass by withoutbending back and compressing the spring D and this would permit theapparatus to move toward the rail were it not for the auxiliar arm, Dpivoted on the frame member 1 andhaving a roller D? adapted to engagethe rail web D when the roller 1) moves back to clear the angle late,and this roller. D is at that time orced into engagement with the web ofthe rail by the rotation of the arm D transmitted through the tie linkD. For normal operation, the position of the parts is as shown in fulllines but when the guide roller reaches an angle plate, the furtherforward movement f the apparatus brings the parts in the positionshownin dotted lines until the angle plate is passed, when the springsnaps the guide back into the full line position.

In Figure 4, is shown a diagrammatic side elevation of the apparatus andassociated parts. At E, we have theexcavating machine with its electricmotor connected by the cable E which may be wound on or, oil the reel Ewith the generator E on a portable frame E which generator is driven byrovides the power to operate the motor ontlie ballast cleaning. machine.The cable onthe reel is of considerable length. The-motor generator setis placed at rest between the tracks within the clearance spaceimmediately behind the ballast cleaner. The engine is, started and assoon as it comes up to speed, the-ballast cleaner is put, intooperation. It propels itself forward doing its work, drawing the cablees the reels until the cable is all pulled out. The crew then moves'themotor generator set up again by hand or by lifting it onto the hand car,winding on the cable until the motor generator set is up to the ballastcleaner. his may bed'one without stopping the operation. The motorgenerator set is placed on the ballast between the tracks again and theoperation is repeated. This ma go on indefinitely.

It is evident t at .I have shown in my drawings an operative device,still many changes might be made in size, shape, or arrangement of partswithout departing materially from the spirit of my invention, and 1wish, therefore, that they may be re garded as in a sense, diagrammatic.

The use and operation of my invention are as follows:

' The 'motor generator set and the ballast cleaning machine willnormally be carried on hand cars or trucks from the storage lace-to theplace where the are. to be used.

he crew will dig out the allast from'between the tracks for a shortdistance so'as to make a hole in which the ballast cleaner may operate.The ballast cleaner will be placed on the ballast above this hole withthe excavator in working position; The

crew' will then place the motor generator set in the space between thetwo tracks immediately behind the. ballast cleaner and couple up thecable between the motor generator the clear space between thetwo tracks,but

also some of the ballast between individual ties of each track. As thecleaner propels ,itself'forward, this clean ballast is returned to thehole behind the point of excavation and-the operators can move part ofit backinto the space .between the mdividual ties,

so the process continues with the ballast cleaner moving forward underits own power. If a train goes by, the crew merely steps to one side andthe cleaner can continue its operation because it is in the spacebetween the tra'cks where no part of any car ever comes. The ballastcleaner progresses forward drawin'g its power through the cable leadingto the motor generator set, but the.

enerator set remains at rest until' motor the cab e is all payed out.Then the crew lifts up the motor generator set and puts it.

down behind the ballast cleaner and repeats the process. This willcontinue indefinitely 'untilthe job is done.

It will be evident that with the power available for propelling theballast cleaner, it might under some conditions be desirable to mountthe motor generator set on runners and have it hauled alon the right ofway by the forward moving allast cleaner, and this, under someconditions, would be done.

I claim:

1. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double trackrailway,of means engaging one eif'the track rails for guiding it along a pathparallel with the track, the entire mechanism being so arranged andpositioned that trains can pass on either track withoutinterferingcleaning ballast arranged "to travel in the clear spacebetween the tracks of a double track railway, of means engaging one ofthe rails of each track for guiding it along a path parallel with thetrack, the entire mechanism being so arranged and positioned that trainscan pass on either track without interfering therewith. Y

3. The combination with a machine for cleaning ballast arranged totravel in the clear space between .the tracks of. a double trackrailway, of yieldingi'means engaging one of the track rails for guidingit along a path parallel with the track, the entlre mechanism being soarranged and positioned that trains can pass on either track withoutinterfering therewith.

' 4. The combination with a machine for cleaning ballast arranged totravel-in the clear space between the tracks of a double track railway,of yielding means en aging one of the rails-of each track for i ing italong a path parallel with the trac the entire mechanism beingsoar-ranged and positioned that trains can pass on either track withoutin rfering therewith.

' 5. The dJnbination with a machine for cleaning ballast arranged totravel. in the clear space between the tracks of a double track railway,of means engaging the web of one of the track rails for guiding it alonga path parallel with the track, the entire mechanism being so arrangedand positloned that trains can pass on either track without interferingtherewith.

6. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of means engaging the web of one of the rails of each track for guidingit along a path parallel with the track, the entire mechanism being soarranged and positioned that trains can pass on either track withoutinterfering therewith.

7. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of yielding means engaging the web of one of the track rails for guidingit along a path parallel with the track, the entire mechanism being soarranged and positioned that trains can pass on either track withoutinterfering therewith.

8. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of yielding means engaging the web of one of the rails of each track forguiding it "along a path parallel with the track, the entire mechanismbeing so arranged and positioned that trains can pass on either trackwithout interfering therewith.

9. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of means engaging the web of one of the track rails for gulding it alonga path parallel with the track, and automatic means associated with theguiding means for compensating for any irregularities in the surface ofthe web met by the guiding means as they travel along, the entiremechanism being 30 arranged and ositioned that trains can pass on eithertr therewith.

It). The combination with a machine for without interfering cleaningballast arranged to travel in the clear space between the tracks of adouble track railway, of means engaging the web of one of the rails ofeach track for guiding it along a path parallel with the track, andautomatic means associated with the guiding means for compensating forany irregularities in the surface of the web met by the guiding means asthey. travel along, the entire mechanism being so arranged wd itionedthat trains can pass on either trac without interfering therewith.

11. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of yielding means enga ing the web of one of the track rails for gui ingit along a path parallel with the track, and automatic means associatedwith the guidin means for compensating for any irregularities in thesurface of the web met by the guiding means as they travel along, theentire mechanism being so arranged and positioned that trains can passon either track without interfering therewith.

12. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of yielding means engaging the web of one of the rails of each track forguidlng 1t along a path parallel with the track, and automatic meansassociated with the guiding means for compensating for anyirregularities in the surface of the web met the entire mechanism beingso arranged and positioned that trains can pass on either track withoutinterfering therewith.

13. The combination with a machine for cleaning ballast arranged totravel in the clear space betweenthe tracks of a double track railway,of means engaging one of the track rails for guiding it along a pathparallel with the track, said means being adapted to guide the apparatusalong a straight path independent of any irregularities in the railsurface engaged by it.

14. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double Illtrackrailway, of means engaging the web of one of the track rails forguiding it along a path arallel with the track, said means being a aptedto guide the apparatus along a straight path'independent of anyirregularities in the rail surface engaged by it.

15. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of means engaging the web 126 of one of the track rails for guiding italong a path arallel with the track.

16. T e combination with a machine for cleaning ballast arranged totravel in the clear spacebetween the tracks of a double 1 track railway,of means .engaging the web of one of the rails of each track for guidingcleaning ballast arranged to travel in the clear space between thetracks of a double track railway, of yielding means engaging the web ofone of the rails of each track, for guiding it along a path parallelwith the track. 1 19. The combination with a machine for cleaningballast arranged to travel inrthe' clear space between the tracks of adouble track railroad, of guiding means therefor comprising two pivotedarms, yielding means for thrusting the end of one of them intoengagement with the rail web and a connection between them whereby onlyone arm at a time can come into engagement withthe web.

20. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railroad,of guiding means therefor comprising two pivoted arms, yielding meansfor thrusting the end of one of them into engagement with the rail weband a connection between them whereby only one arm at a time can comeinto engagement with the web, said connection comprising a link pivotedat either end on one of said arms,

the length of the link being such that the arms are outwardly diver ent.

21. The combination with a machine for cleaning ballast arranged totravel in the clea space between the tracks of a double trac railroad,of guiding means therefor comprising two pivoted arms, yielding meansfor thrusting the end of one of them into engagement with the rail weband a connection between them whereby only one arm at a time can come1nto engagement with the yveb, there being a pair of such arms oneither. side of the machine whereby the machine is ided between theinner rails of each of t e two tracks.

22. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railroad,of uiding means therefor comprising two pivoted arms, yielding means forthrusting the end of one of them into on agement with the rail web and aconnection between them whereby only one arm at a time can come intoengagement with the web, said connection comprising a link pivoted ateither end on one of said arms, the length of the link being such thatthe arms are outwardly divergent, there being a pair of such arms oneither side of the machine whereby the machine is guided between theinner rails ofeach of the two tracks.

23. .The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railroad,of iding means therefor I comprising two pivoted arms, yielding meansfor thrusting the end of one of them into engagement with the rail weband a' connection between them whereby only one arm at a time can comeinto engagement w1th the web, the distance between the rail engagingends of said arms being greater than the normal lengthof the angle barsused to tie'the rails together,

24. The combination with a machine for cleaning ballast-arranged totravel in 'the clear space'between the tracks of a double trackrailroad, of\ guiding means therefor comprlslng two pivoted arms,yielding means for thrusting the endv of one of them into engagementwith the rail web and a connection betweenthem whereby'only one arm at atime can come into engagement w1th the web, said connection comprising alink pivoted at either end'on one of said arms, the length of the linkbeing such that the arms are outwardly divergent, the dis' tance betweenthe rail engaging ends of said arms being greate-rfthan the normallength of the angle bars used to tie'the rails together. I i

25. The com'bination'with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a doubletrack railroad,of guiding means therefor comprising two pivoted arms,- yielding meansfor thnusting the end ofone of them into en agement with the rail weband a connection between them whereby only one arm at a time can comeinto engagement with the web, there being a pair of such arms on eitherside of the machine whereby the machine is guided between the innerconnection between them whereby only one I arm at a time can come intoengagement with the web, said .connectlon oomprlsing a. link pivoted ateither end on one of said arms, the length of the link beingsuch thatthe arms are outwardly divergent, there being a pair of sucharms oneitherside of the machine whereby the machine is guided-between theinner rails of each of the two tracks. 7

27. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks ofa double track railroad',of guiding means therefor comprising two pivoted arms, yieldlng meansforthrusting the end of one of them into engagement with the rail web and aconnection between them whereby only one arm at a time can come intoengagement with the web, the relation between the arms being such thatwhen the nearmost arm is in engagement with the rail connecting meansand thereby raised out of contact with the rail web, the end of theforward arm is drawn into engagement with the rail web.

28. .The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railroad,of guiding means therefor comprising two pivoted arms, yielding meansfor thrusting the end of one of them into engagement with the rail weband a connection between them whereby only. one arm at a time can comeinto engagement with the web, the relation between the arms being suchthat when the rearmost arm is in engagement with the rail connectingmeans and thereby raised out of contact with the rail web, the end ofthe forward arm is drawn into engagement with the rail web.

29. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railroad,of guiding means therefor comprising two pivoted arms, yielding meansfor thrusting the end of one of them into engagement with the nail weband a connection between them whereby only one arm at a time can comeinto engagement with the web, there being a pair of such arms on eitherside of the machine whereby the machine is guided between the innerrails of each of the two tracks, the relation between the arms beingsuch that when the rearmost arm is in engagement withfthe railconnecting means and thereby naised out of contact with the rail web,the end of the forward arm is drawn into engagement with the rail web.

30. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railroad,of guiding means therefor comprising two plvoted arms, yielding meansfor thrusting the end of one of them into engagement with the rail weband a connection between them whereby only one arm at a time can comeinto engagement with the web, saidconnection comprising a link pivotedat either end on one of said arms, the length of the link being suchthat the arms are outwardly dive nt, there being a pair of such arms oneit er side of the machine whereby the machine is ided between the innerrails of each 0 the two tracks, the relation between the arms being suchthat when the rearmost arm is in engagement with the rail connectingmeans and thereby raised out of contact with the rail web, the end ofthe forward arm is drawn into engagement with the rail web.

31. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,having a reciprocating ballast cleaning screen and means for driving it,of a propelling member, a ratchet clutch associated therewith, andaconnection between such ratchet clutch and the screen driving mechanismwhereby the apparatus is forwardly propelled as the screen operates.

'32. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of a reciprocating screen, an eccentric shaft, and a driving connectionbetween them, means for rotating the shaft, a running gear for themachine, and a driving connection between it and the screen drivingmeans.

33. The combination with a machine. for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of a reciprocating screen, and

eccentric shaft, and a driving connection between them, means forrotating the shaft, a running gear for the machine, and a driv-' ingconnectlon between it and the screen driving means, said connectioncomprising a ratchet clutch lever and a link connecting it and theeccentric driving connection.

34. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of a reciprocating screen, and eccentric shaft, and a driving connectionbetween them, means for rotating the shaft, a running gear for themachine, anda driving connection between it and. the screen drivingmeans, said connection comprising a ratchet clutch lever and a linkconnecting it and the eccentric driving connection, the length of saidlever being adjustable to vary the travel of the machine.

35. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of a sliding support therefor, and means for moving said machine forwardupon such sliding support.

36.. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of a sliding support therefor,

and means for moving said machine forward prising an endless groundengaging belt and k means for driving it, the forward end of the machineonly, being supported on the sliding gupport, the rear end beingsupported on the 38. The combination with a machine for cleaning ballastarranged to travel in the clear space between the tracks of a doubletrack railway, of supporting runners beneath the forward end of themachine and means located toward the rear of the machine for propellingit forward.

'39. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of supporting runners beneath theforward end of the machine and meanslocated toward the rear of the machine for propelling it forward, saidmeans comprising an endless ground engaging belt.

40. The combination with a machine for cleaning ballast arranged totravel in the clear space between thetracks of a double track railway,of supporting runners beneath the forward end ofthe machine and meanslocated toward the rear of the machine for propelling it forward, saidmeans comprising an endless ground engaging belt, said belt beinginterposed between the ground and a rearward continuation of therunners,

which continuation of the runners forms a sliding bearing on the uppersurface of the ground engaging belt.

41. In an excavating machine, a frame supporting runner beneath theforward end of the machine and a ground engaging driving belt beneaththe rear end of the machine, 7

said belt being in line with the runner, the

' weight of the machine being applied to the in the ground engagingdriving belt by rearward," extensions of said runners.

42. A machine for cleaning ballast arranged to travel in a clear spacebetween the tracks of a double track railway, comprising a anexcavating, propelling and cleaning machinery and drivin motor and amotor generator set, and a exible extensible connection betweensaidmotor and said generator set.

43. The combination with 'a machine for cleaning ballast arranged totravel in a clear space between the tracks of adouble track railway, ofmeans for guiding it along a path parallel with the track, the entiremech-' anism being so arranged and positioned that trains can pass by oneither track without interfering therewith, means for cleaning theballast, and means for advancing the entire mechanism, in response tomovement of the ballast cleaning means.

44. The combination in a machine for cleaning ballast, of a framearranged to travel in the clear space between the tracks of a doubletrack railway, means on said frame for removing the ballast from the Iroadbed, means for screening the ballast and returning it to theroadbed, and means assothe entire mechanism being located on the framein such position that trains can pass on either track withoutinterfering with the.

frame and the mechanism carried thereby.

45. The combination with a machine for cleaning ballast arranged totravel in the clear space between the tracks of a double track railway,of ballast excavating and ballast cleaning means, a driving mechanismtherefor, and means driven thereby for propelling the apparatus as itworks.

In testimony whereof, I aflix my si ature resence of two witnesses thls29th day of eptember, 1919. I

HOWELL D. PRATT. Witnesses:

PAUL FREEDLEY, F. Am Simmons

